MountainGeek

Yeah I really would like to know whether Nov is merely a "head fake" before we torch through half our prime climo in Dec/Jan, or a glimpse into perhaps the base state setting up for winter. Guess we'll find out in a few weeks......

IMO seeing coastals pop up is a good thing regardless since it means there's a chance this winter pattern might feature at least some favorable periods. All for a nasty -EPO and -NAO as long as it's not overdone to the point where we're getting suppression. I'll be thrilled to see our SE friends cash in on Miller A's that start in AL as long as they eventually get around to mauling us. But I'll take a pass on smoking cold cirrus while watching Atlanta get hammered by a southern slider.

Wow -- incredible amount of information and very informative with lots of detail and explanation as to what's going on. I found this section re NAO prediction fascinating -- and quite an interesting history lesson re the contributions of @UniversesBelowNormal: Utilizing North Atlantic SSTs During Summer as an NAO Predictor for Cold Season Perhaps one of the most skilled forecasters on a forum replete with talented meteorologists and hobbyists alike, in americanwx.com, "StormchaserChuck", now known as "UniversesBelowNormal", devised a formula over a decade ago that predicts the mean aggregate state of the NAO for the ensuing winter using the SSTs in an area of the north Atlantic. This methodology is strongly endorsed as one of the more accurate predictors available for the mean state of the winter NAO. In fact, had Eastern Mass Weather considered it last season, the outlook would have been much more successful. The following methodology is a wonderful illustration of the delayed feedback between sea and air that represents the very essence of the elaborate system of atmospheric oscillations that is so often referenced. "In 2006 on a site called easternuswx, elaborate research was done with North Atlantic SSTs, showing high lagging predictive value for following Winter's NAO/AO. The correlation factor was higher than 0.4, and there was advantage over decadal cycles. Meaning, it would predict years that reversed the decadal trend. The index was very accurate in predicting the +NAO for the 2006-2007 Winter, and got much attention after a topic called "This will be the warmest Winter on record for the US" (It was the 7th warmest). Since then the index has performed wonderfully after the fact: 2018-19: +NAO signal/+NAO winter....Verified 2017-18: Strong -NAO signal/+NAO Winter....Failure to Verify 2016-17: Strong - NAO signal/ Weak -NAO Winter .. Verified 2015-16: +NAO signal/ +NAO Winter ... Verified 2014-15: Strong - NAO signal / +NAO Winter ... Failure to Verify 2013-14: Strong +NAO signal / +NAO Winter ... Verified 2012-13: slight -NAO signal / strong -NAO Winter ... Verified 2011-2012 neutral NAO signal / +NAO Winter ... Null 2010-2011: Strong -NAO signal/ Strong -NAO Winter ... Verified 2009-2010: Strong -NAO signal / Strong - NAO Winter ... Verified 2008-2009: weak -NAO signal / weak -NAO Winter ... Verified 2007-2008: -NAO signal / +NAO Winter ... Failure to Verify 2006-2007: +NAO signal / weak +NAO Winter ... Verified 2005-2006: strong +NAO signal / +NAO Winter ... Verified In fact, the predictor has now verified 10 times, failed 3 times and predicted a neutral ENSO once. The value of this predictor as a forecasting tool has proven high, although the scientific fundamentals are a bit weaker in in the opinion of this writer. The index is a measurement of May 1 - Sept 30 SSTs in the North Atlantic. It's correlated to following November-March NAO/AO (+6 month lag). The index is a composite of 2 areas in the North Atlantic (blue box - red box). When blue box is cold SSTs, negative NAO Winter. When red box in warm SSTs, negative NAO Winter. For compare, and red box is 65% value of blue box anomaly (so -1 blue +0.65 red is same thing). Visa versa. The index this year is indicative of a moderately robust -NAO, at -.55 to -.60, as per the north atlantic SSTS between May and September:

Also I like seeing as much early cold as we can over the GL region.....the quicker we can get the lakes cooled down and partially frozen, the less moderating effect they have on the cold shots coming down from Canada. Since so many of our events have at least a portion of the subforum flirting with the freezing line, every degree matters.

Yeah I never count March out -- it can be a lot of fun sometimes if things line up just right. In a couple of the "bad" years, our best storm of the season was mid or late-March. It will be interesting to see if there's any similarity to 2009 this time around, one obvious difference is the Oct cold in 2009 seemed much more widespread and this year it was cold west/warm east.

November is the new January!

Thanks -- don't forget to mix in general atmospheric chaos/butterfly effect, a VERY short recorded data timespan (relative to all of past history).....trying to predict longer term and seasonal weather has lot of parallels to picking numbers or trying to "game" a slot machine. Quite a few of the folks who participate in this forum enjoy hitting the casino as well...I don't think that's a coincidence. And the nice thing about weather is when it pulls the rug out from under you, you only suffer a hit to your pride and not your pocketbook.

Depends on the lag duration....on the positive side: solar was very low last year as well so if there's, say, a 1 year lag, we're getting any benefits now and next winter might get even more "help" in that area. If there's not a lag, then we're getting any benefits as we go in real time. All good, right? But remember it's never only one factor -- the ultimate winter outcome is a combination of dozens of known factors (and maybe even more that we still don't fully understand yet). And of course the possible links between low solar, HL blocking, colder winters, etc are still being explored, so no guarantees.

Quite so.....we got 6 inches on Nov 15 last year.....

We got 5 or 6 inches last year on Nov 15, maybe an early start again for this season? Would be really nice to get a little appetizer on the board up front, say a couple inches or even some mood flakes. The years where we're completely shutout with torches or "no chance" patterns until late Feb or March are the worst......

Ah yes, good point that the ensemble washout wouldn't "see" brief warming periods related to return flow, etc....which then start to factor back in closer in time and moderate the original extreme. I think your approach of analyzing the background state and other supporting factors (or lack of)....like the cross-polar flow you mentioned.....is a smart way to evaluate whether the LR might be on to something or if it is just out to lunch (or trying to lure weenies into early reapings).

Would it be reasonable to say that, more often than not, most LR modeled extremes (hot, cold, HL blocking, etc) tend to moderate somewhat as we get closer in time? That has been my general experience. I figure it has something to do with compounding of modeled errors out in time creating a tendency to overdo things a bit.....

Interesting thoughts from Cranky on the upcoming winter: http://www.stormhamster.com/entry2/e101819.htm Something you've seen me post since the summer and the process continues to reinforce. We just watched two October storm setups born off this very pattern being emulated by our stream flows. We'll watch the next attempt to do the same. Does this persist into winter? If so I continue to say we could see several more classic arctic outbreaks and classic coastal winter storm tracks. I am not talking about a ceaseless onslaught. The overall winter pattern in my opinion likely features the blander milder November, a colder active December, then January/February maybe a little above norms, with March/April possibly featuring another late period colder/active return. Yet within all of that? Expect a few more classic outbreaks and storm tracks. Of course, it is still early, and it will be another 4 to 8 weeks before we truly know if the support we see now is still in play by then.

Got any verification scores for handy for that model? Also early on last year it seems like almost every model in the LR seemed to be predicting a big -NAO that just kept sliding out into the future and never actually materialized. Maybe we'll play opposite again this year to our advantage.

Wow -- just checked in to see if the winter discussions are starting, and was pleased to find quite a lot of solid technical discussion and good data points! Here's to hoping we can keep this "quality post" trend going...and looking forward to another fun winter tracking season. Pleassseeee just once -- it's time we had a low solar + Modoki + neg NAO + warm blob epic winter. On a more serious note, I'm liking what appears to be a more favorable PAC shaping up, since the PAC really hurt us several times last year.